| Question | Answer |
|---|---|
| An electric current in motion flows | quickly and invisibly from one place to another. |
| In a closed circuit, or loop, electric charges | flow from a power source through wires that provide a path. |
| A cut wire and/or an "off switch" are two examples that | "open" or "break" a working "closed" circuit. |
| The flow of electric charges is not | the same in all materials |
|
Conductors are materials through which |
electric charges can move easily. |
| Most metals such as copper, gold, and silver, are | good conductors |
| Insulators are materials through which an electric charge | moves with difficulty. |
| Plastic, rubber, glass, and dry wood are | good insulators that keep electric current flowing and prevent people from getting shocked by handling bare wires. |
|
Batteries (direct current) and electrical outlets (alternating current) are |
energy sources for circuits. |
| Resistors transform energy into | other forms of energy such as light bulbs or machines. |
| In a Series Circuit electric charges can flow in only | one path. |
| In a Series Circuit, any break in the loop | stops the current from flowing. |
| In a Parallel Circuit electric charges have The current that flows through one path does not have to flow through the other paths. If one loop in the circuit is broken, the current will still flow through the other loops. | two or more paths through which electric charges flow. |
| In a Parallel Circuit, if one loop in the circuit is broken, the current will | still flow through the other loops. |
| Energy is never lost. It cannot be | made or destroyed. |
| Energy can ______________ or change its form. Electricity can change to light, motion can change to sound, and wind can change to electricity. | transform |
| Friction is a force that acts when two surfaces rub together. As a result of friction,______________is given off. |
heat |
| Magnetism is a force that acts on | moving electric charges and magnetic materials. |
| A magnetic field is the _______________________________ in which magnetic forces operate. The exact shape of the field depends on the shape of the magnet. | space around a magnet |
| The magnetic field is strongest at the magnet's ____________ and gets weaker away from the poles. | poles |
| Wherever you are on Earth, one end of a compass needle will point closely to Earth's geographic _________________ | north pole. |
| Hans Christian Oersted realized that running an electric current through a wire produces a ___________________________ | magnetic field. |
| To make an electromagnet, you pass an | electric current through a coiled wire. |
| Electromagnets are useful because you can | turn them off when you do not want to attract objects. |
| Motors in many appliances (ceiling fans, hair dryers) use electromagnets to change electrical energy into ___________________________, the energy involved in motion. | mechanical energy |
|
Sliding a magnet back and forth within a coiled wire makes |
electricity |
| Spinning a _____________ wire around a magnet makes electricity. | coiled |
| The faster a magnet or coiled wire is moved, the stronger the | electric current becomes. |
| A generator is a machine that produces electric energy by turning | coils of wire around powerful magnets. |
| A wind turbine or water flowing through a dam can supply the motion that | spins a generator |
